Can a faulty diverting valve burn out circulating pump?

Hi there,

I had a circulating pump replaced a few months ago (was very old) and it ran ok for a while, but then burnt out the coils (blew the fuse etc).

At the time I thought it might have been either the crap in my system or water that was dripping onto the pump from a leaking valve.

I replaced the pump myself last weekend (a replacement that the plummer got replaced by the shop and I've been flushing the system this weekend to find that the diverting valve looks like it is playing up (Honeywell Sundial Y Plan).

It seems to work ok most of the time, but then sometimes when I turn off the hot water from the controller (so that just the central heating is running) the pump seems to stop.

I was wondering if this could have burnt out the previous pumps where the water has nowhere to go and straining?

Cheers, Mark.

The Y plan is never shut, there is always a path open to either the HW or CH.

So this component is unlikely to be the problem.

Most pumps will stand pumping into a closed valve although they get quite hot.

If they are in free air to cool them then most will survive several days like that.

If covered by insulating clothes then they can overheat so much that they will burn out.

If you drip water onto a pump you should expect it to be damaged!

Tony

Thanks for the replies.

It seems to be going ok at the moment, but I was wondering if it could cause poblems if the valve was stuck in the position to heat the hot water tank constantly?

Just that I'm trying to work out if it's jammed on the hot water output now?

Simon - you said it's either HW or CH - can it do both at the same time?

The central heating seems fine now.

Thanks, Mark.

One or other or both!]

The pump will be fine as long as there is a flow to somewhere.

Feeling the temperatures of each port will indicate which position its in!

Tony

Ok - thanks for that - I'll see how it goes.

Although it can and does do both at the same time, it will only be for a short time. As soon as one side is satisfied it automatically goes to the non satisfied side. It only stays in mid position if both sides are not satisfied.
If the pump stops when just the CH is running I assume the boiler would also stop. I think you may be saying, you can't get CH only but you can get CH along with HW (even if for short time).
If this is so I would suggest the valve is not moving to the CH position due to incorrect wiring or failed motor. Or if it does move to CH only then failed micro switch within the actuator head of valve.